NULL Pointer Dereference Affecting kernel package, versions *


Severity

Recommended
low

Based on Red Hat Enterprise Linux security rating.

Threat Intelligence

EPSS
0.04% (5th percentile)

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  • Snyk IDSNYK-RHEL8-KERNEL-7185573
  • published3 Jun 2024
  • disclosed30 May 2024

Introduced: 30 May 2024

CVE-2024-36925  (opens in a new tab)
CWE-476  (opens in a new tab)

How to fix?

There is no fixed version for RHEL:8 kernel.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel package and not the kernel package as distributed by RHEL. See How to fix? for RHEL:8 relevant fixed versions and status.

In the Linux kernel, the following vulnerability has been resolved:

swiotlb: initialise restricted pool list_head when SWIOTLB_DYNAMIC=y

Using restricted DMA pools (CONFIG_DMA_RESTRICTED_POOL=y) in conjunction with dynamic SWIOTLB (CONFIG_SWIOTLB_DYNAMIC=y) leads to the following crash when initialising the restricted pools at boot-time:

| Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008 | Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP | pc : rmem_swiotlb_device_init+0xfc/0x1ec | lr : rmem_swiotlb_device_init+0xf0/0x1ec | Call trace: | rmem_swiotlb_device_init+0xfc/0x1ec | of_reserved_mem_device_init_by_idx+0x18c/0x238 | of_dma_configure_id+0x31c/0x33c | platform_dma_configure+0x34/0x80

faddr2line reveals that the crash is in the list validation code:

include/linux/list.h:83 include/linux/rculist.h:79 include/linux/rculist.h:106 kernel/dma/swiotlb.c:306 kernel/dma/swiotlb.c:1695

because add_mem_pool() is trying to list_add_rcu() to a NULL 'mem->pools'.

Fix the crash by initialising the 'mem->pools' list_head in rmem_swiotlb_device_init() before calling add_mem_pool().

CVSS Scores

version 3.1